Pros and Cons - 90 gal vs. 75 gal.

Bigger isn't necessarily better. Usually it is, but.... as reefman said in a 75 you're getting more surface area to depth ratio which helps with gas exchanges a bit, plus the lighting will be a bit more effective too. However with softies and monti's, lighting isn't a huge deal. Usually it's a huge advantage to go bigger if you're increasing the size of the footprint of the tank (ie upgrading from a 4' to a 6' tank is where you'll get the best impact of size difference). Adding a few inches height-wise adds a bit more stability in water params, but not really much else.

That all being said, I'm just playing devil's advocate for the other side of the coin. If I were you I would still get the 90 and build a stand

 

I would go with the 90 but if you do you will most likely have to upgrade you lights or at least add to them to compensate for the extra depth.

If it was me I would go the extra and get a 120, the 75 and the 90 have exactly the same foot print 48 x 18. The 120 is 48 x 24 which is an extra 6" which will allow room for allot more coral. I like my 75 but my next tank is going a 120.

 

Have I mentioned that I love this site? It's great to have experienced "tankers" to share their knowledge.

So thank you, thank you, thank you! Keep the input coming!

 

That probably the best set up for more space. Other wise you don't gain much with a 90 vs. a 75. 120 gal is where its at!!!;D

 

...scuba gear...

Kidding aside, when I purchased my first big tank, it was a long 100.
I have come to like long tanks for several reasons.
1) less lighting needed to reach the bottom of the tank.
2) swimmers, like tangs, get longer runs before having to U-turn.
3) greater surface area for gas exchange.
4) more of a "panorama" view.
Even with a tank that is only 20 inches deep, I still find it easier to work with a stepstool! I think I've gotten spoiled.

Good luck with whichever you decide on!

 

are you going with AGA tank with a built in overflow. if yes i had the 90 and i think it really needs 2 overflows for good circulation. i say the best option is between the 75 or the 120


edit: the 90 giving you more space is a plus though, but what would decide it to me is the stand nice or not. if it looks like something i could throw together then i would get the 90

 

Yes - we have been look at 90 gal. with the single overflow, although we have seen a 90 gal. with the double overflow. Hmmm. . . it looked like more of a pain to plumb into the sump, but it's probably worth it???? Does it make any difference if it is a corner overflow or back overflow?

 

i don't remember the statistics, but i think there is a difference in flow rate between a acorner and a back one. i think it would be worth it to have two backs that way you can have less ugly powerheads in the tank. mine had one back overflow, it was pretty sad how much i had to turn the pump down to keep the tank from overflowing


the 90 was a pretty good tank, but i had two complaints it was two tall for me to reach the bottom easily (im 6'3), and the overflow gph. but other then tank it was fine. but i guess really how much stuff can a tank be judged on besides the dimensions and overflow rate

if you have the option i would go with either a longer tank or a wider one so its not so tall.

 

I have had both a 75g and a 90g. By far, the 90g is superior. Much better viewing. The canopy does not cut off my view of the tank so much. I am only 6'2", but it is tall enough for me to have to stoop a bit to get the full view of the 75. It's not like that with the 90.

 

if money isnt such a huge concern I would go with the 90 and get the bigger lights to match